French Foreign Minister Bernard Kouchner, his British counterpart David Miliband and Washington's top diplomat for Africa, Jendayi Frazer, were all due in Kinshasa and Goma before heading to Rwanda.

EU development commissioner Louis Michel, speaking in Kinshasa, said Friday that Kabila and Kagame had agreed to meet at a summit in Nairobi under the aegis of the United Nations and the African Union.

Michel said both leaders were clearly sincere about "opting for dialogue and putting an end to the reasons that are undermining the east" of the country -- the scene of protracted fighting between rebels and government forces.

In Goma, tension remained high amid a fragile ceasefire as Tutsi rebel troops led by Laurent Nkunda laid siege at the doorsteps of the strategic eastern city.

Government forces abandoned Goma on Wednesday as the rebels advanced on the city, leaving just 850 United Nations peacekeepers between Nkunda's forces and Goma.

The UN refugee agency UNHCR said it had received credible reports that rebels had looted and burned camps for displaced people.

"We are extremely concerned about the fate of some 50,000 displaced people living in these camps, which include the UNHCR-administered sites of Dumez, Nyongera and Kasasa," spokesman Ron Redmond told journalists.

Before leaving France, Kouchner lamented the violence plaguing eastern DRC, telling French radio Europe 1: "This is a massacre such as Africa has probably never seen, which is taking place virtually before our eyes."

UN Human Rights Commissioner Navi Pillay said Congo's routed government forces had gone on a rampage of lootings, killings and rape over the past few days in Goma.

She urged the government to take "swift and significant action" to control their troops and protect civilians.

"What happened in Goma should not have happened, as most violations were committed by looting soldiers belonging to the government forces," she said.

Pillay also accused rebel forces of rights abuses, such as firing indiscriminately at a clinic where government soldiers had fled.

Some 220,000 people have now been displaced since fighting broke out in August, bringing to more than one million the number forced from their homes in Nord-Kivu, a province bordering Rwanda that totals five million.

Nkunda, who says he is protecting the Tutsi population, has accused the DRC army of colluding with Rwandan Hutu rebels of the Democratic Forces for the Liberation of Rwanda (FDLR) in the Nord-Kivu region.

The DRC government, for its part, has accused Rwanda of aiding Nkunda's National Congress for the Defense of the People (CNDP).

The head of Uruguay's military, which contributes 1,300 troops to the 17,000-strong UN peacekeeping mission, said Friday the CNDP was "backed by tanks" and "artillery" from Rwanda.

General Jorge Rosales said it was "not easy to identify rebel forces," but indicated that there is a "high probability that troops from Rwanda are operating in the area."

"These (rebel) troops are backed by tanks, something that general Nkunda had not had until now," he said.

Rebel forces were within two kilometers (1.2 miles) of the UN peacekeepers, eight kilometers north of Goma, Uruguayan officials said.